Saturday, August 04, 2007

Heat flow by convection can be visualized by Schlieren photography in which density differences can be clearly seen. Schlieren photography is closely related to what we commonly refer to as watching the heat rise off hot asphalt, but is much more sensitive (a paper by Gary Settles gives several examples). Horatio Algeranon (a very punny anonymouse) picked up on this, and found a picture showing that the heat flow from a charcoal grill is pretty much straight up. But even Ethon knew this, if he stands to the side when grilling his liver McClimateAudit burgers, things are relatively cool, but bend over and put his beak above the coals, and sure enough it gets fried.

Which brings up to one of Anthony Watts' favorite surface station views

112 comments:

Anonymous
said...

Another funny thing about rising hot air is that it has to be replaced by an equal amount of heavier, colder air. It thereby establishes an incoming flow of cool air that will likely fan the surrounding objects that are at the same height as the heat source.

Besides the fact that heat rises -- and draws cooler air in from the surroundings -- there is something clearly the matter with assuming that the trash barrel impacts the temperature trend at that station.

Are we really to believe that the temperature is being taken at the very moment when the trash burning is occurring?

That would presume that whoever is recording the temperature is a total and complete idiot.

This is what really bugs me about Watts' project. He puts these photos up and never bothers to do any research about the history surrounding them and/or to determine if what he thinks they signify -- with regard to effect on temperature -- is actually the case. Or if he does do such research, he does not let onto it.

For example, is that barrel actually being used at that location? if so, how often?

What and how much of it is being burned? A few pieces of paper?

When (if ever) is the barrel being used in that location relative to when temperatures are recorded?

there is going to be a certain amount of heat radiation to the sides, but how much? how long does it last? What effect does the air being drawn in from the sides have on the complete picture?

Watts has done none of his homework with regard to such photos.

A photo with a barbecue or trash burning barrel next to a temperature station means nothing without context.

In a perfect world, barbecues and trash incineration barrels would never be found anywhere within 100 feet of a temperature station.

But you know what? We don't live in a perfect world and sometimes it makes sense to do a reality check to make sure that one's first impressions don't amount to making a mountain out of a grassy Rabett knoll.

I've got a small charcoal furnace in my drying green. Weather permitting, when I am melting copper tommorrow, I can put a thermometer in a box opposite it, and see what effect that has on thermometer temperature.

I'm truly surprised you are using them since its been asserted regularly here that "photos don't matter" ;)

The good news is that I do in fact have three new Stevenson Screens, and I can easily acquire a trash barrel. Once my paint/whitewash experiment is complete, and the surfacestations.org volunteers have as surveyed many of the 1221 USHCN stations we can possibly get, then I'll have time for that experiment. I'm looking to acquire am IR camera to really get a complete picture in addition to air temperature measurements. Would any of you kind folks wish to assist in defraying the costs or help in the experiment?

Just two things missing though from your current photos; wind/mixing ratio, and IR emissions. As I understand it, Schlieren photography relies on density differences in the medium. In this case heated air has different density, so it becomes visible to the photographic method, But IR emissions aren't seen in these photos and as we know that can be a component of localized heating as well.

So while anyone can see that the majority of "visible" heat rises via the photograph of air density differentials, wind/mixing, and IR aren't part of the photo context.

Still the bottom line is that stations used to monitor climate shouldn't be exposed to such potential biases as trash barrels, A/C and the like because sorting out the magnitude of bias and the sign of the bias after the fact is a difficult job.

> Eli walked by a large one > yesterday, there was very little > airflow a few feet to the side.

This is hardly a scientific statement.

It's hardly inconceivable that the effect would be ~1-5 C, more than enough to nullify the thermometer reading.

There's just no reason to have such a suspicious heat source anywhere (~10 m? 30 m?) near a temperature gauge. It certainly raises legitimate questions about the honesty of the reading of that thermometer, and its ability to act as a proxy for the global surface temperature reading in its locale.

What I looked at was how the long grass was moving. There clearly was a difference directly in front of the unit, but more than 20 degrees to the side there was none. That is a scientific observation. You can clearly see the same thing in the Schlieren.

1) Photos can identify some possible microclimate effects, but are useless in terms of quantifying them.

2) The USHCN pre-dates current climatological requirements. People like Jim Hansen had nothing to do with setting it up, and simply had to make do with the data as it existed.

3) While the USHCN data is such that perfectly good numbers can be generated for large-scale trends like nation-wide temperature, this is not at all true for small regions. Weather forecasting will benefit from accurate regional data, and it's an absolute requirement for future climate modeling efforts.

4) Climatologists recognized the deficiencies of the USHCN and, since it is a practical impossibility to fix the existing network, decided to build a new one (the Climate Reference Network). This decision was made years ago, and the CRN is nearly complete.

5) CRN stations were sited in part with a view toward validating prior USHCN data. This was done by ensuring that there would be relatively "clean" USHCN stations near each CRN station so that corrections can be made by means of a comparison of anomaly trends.

6) It is not valid to "throw out" data from a given USHCN station, even if microclimate effects (or other problems such as defective sensors) are apparent, since the comparison with the CRN data will allow the calculation of a valid trend. (An exception might be those that are very distant from a CRN station, but the number of USHCN stations whose data can be validated is so large that any exceptions are unimportant in terms of national average temp trends. Even for such stations, the follow-on USHCN-M program will ultimately allow reliable data to be generated.)

As someone with a meteorological background, AW must have been generally aware of all of the foregoing at the time he began his effort earlier in the year, and yet he started anyway. There's "auditable" CRN comparison data available now, but there seems to be little interest in examining it. Possibly because it doesn't create a basis for attacking the national temp data, as one can do by showing horror-show pictures of "bad" stations and just not talking about the CRN? Imagine that.

So Eli went to the lab today and the bunnies rummaged in the bottom most drawer, where we keep the antiques and came up with a real thermometer which could be read to 0.1C and had a calibration from when NIST was NBS.

So we stuck the thing into a tube and motored it home and went over to the neighbor's place. Eli of the sharp eyes observed where the grass (the long grass, mowing in the city is a sometime thing if your lawn is about 4' x 5' and you are about 80) was moving the most and where it stopped moving. Standing about 3 m away (that is where the chain link fence is, Eli measured a temperature 1.5 C higher standing directly in the middle of where the fan was moving the most air. The A/C was a big sucker too, probably 220 V. Moving about 1 m to the right or left, zippo, nada, nichts. Same temp as ambient.

anon 5:25 pm, I'm sure you'll understand if I tell tou to go to the CRN site and find it yourself. It's not that hard, plus then you'll probably have to read some other stuff that might cause you to become a bit more informed.

anon 9:25 pm, they may or may not have an effect, which is where the whole science thing comes in.

I use wood heat for my house. Hot air rises of course but there is one tbing that I do notice. It gets very hot by the wood stove. In fact, it gets so hot that it is quite uncomfortable to stand near it.

Now I learn that from this blog that this is an illusion. Hot fires do not heat their surroundings. Who would ahve guessed?

CRN data is available.however,you have to "download"it month by month, unlike USHCN data which you get in one gulp.It would be nice if they had a proper download facility.

Studies have started on comparing the two nextworks. 1 found a study showing analysis of a single site.

here is a quote:

"

At the Asheville site, the effect of siting differencebetween the ASOS and CRN led to a ∆Tlocal effect ofabout 0.25 C, much larger than the ∆Tshield effect (about-0.1 C). This local warming effect, caused by the heatfrom the airport runway and parking lots next to theASOS site, was found to be strongly modulated bywind direction, solar radiation, and cloud type andheight. Siting effect can vary with different locationsand regions as well. This term, undoubtedly, needs tobe taken into account in the bias analysis if twoinstruments of interest are separated by a significantdistance."

Anthony, certainly you can check, but my intuitions is that radiant IR will be important unless you have some sort of heat/light source. A furnace, a lamp, a flame, a For air conditioners, radiant heat emission will be minimal. Maybe something from a grill or a trash burn.

Anthony: you are a gentleman in your responses. (even if the picture blog posts are a bit OTT.)

How about getting the paint question finished off? Have you done a lit search. (perhaps others have looked at this before. How about a sit down interview with WMO.) Written a draft paper. Thought through confounding variables and statistical significance?

== Steve Bloom said: ====1) Photos can identify some possible microclimate effects, but are useless in terms of quantifying them.==

Agreed, but the effects should be quantified and the microclimate effects shoud have been documented years ago.

=="2) The USHCN pre-dates current climatological requirements. People like Jim Hansen had nothing to do with setting it up, and simply had to make do with the data as it existed."==

No, the USHCN has been violating its own standards for years. There appears to be no serious compliance mechanism. Will there by compliance at the CRN with its standards?

And Hansen and others who have used the data, are responsible for doing better due diligence then they have.

=="4) Climatologists recognized the deficiencies of the USHCN and, since it is a practical impossibility to fix the existing network, decided to build a new one (the Climate Reference Network). This decision was made years ago, and the CRN is nearly complete."==

Climatologists made no attempt to fix the problems with the current network; nor even document them. That's shameful.

=="5) CRN stations were sited in part with a view toward validating prior USHCN data."==

You keep saying this Steve but never explain it. How can the CRN validate the robustness of decades old data? I'm not talking trends here.

=="6) It is not valid to "throw out" data from a given USHCN station, even if microclimate effects (or other problems such as defective sensors) are apparent, since the comparison with the CRN data will allow the calculation of a valid trend."==

The trend is not the issue. The issue is the accuracy of the temperature for the last hundred years. Just saying "it warmed" is insufficient. We want and require accuracy. And that would require a root and branch audit of USHCN stations.

I seem to remember from material science classes that the TiO2 pigments used on Stevenson boxes are >98% or so effective reflectors of IR and VL radiation. Can anyone source that, I seem to have tossed out a bunch of stat sheets on protective coatings I used to have.

I'm curious what deviation in trend measure the apparent <4% of USHRN sites shown to be non-compliant with regulations at surfacestation.org might have on climate trend calculations. My intuitive guess is about 25C/1C, assuming they are all positive and the deviations can be shown to have increased over time, correlative to total averaged trends of all stations.

Has anyone started working on an analysis of data collected from a statistically meaningful number of "poorly sited" vs. "well sited" stations in order to determine how much of the assumed recent warming is simply a product of data artifacts?

I am guessing these are supposed to be infared photos to fool the anonymice. Problem is a lot of us simple folk use or have used trash barrels in the past. When you get some cardboard in there really going, the can itself starts to glow.Stop trying to feed us garbage camera tricks.A lie by camera is still a lie.

Well the amount of warming that is a data artifact is the difference between the compiled numbers and the actual warming needed to blanch corals and increase sea surface temps, dry up the Amazon, increase the frequency and duration of heat waves, alter rain patterns, show an almost identical warming from boreholes, make species move upward and poleward, delay sea ice formation and advance its melting, decrease glacier mass balance in the way Tamino has well summarized on Open Mind and probably a few other things too. Exactly how much difference that is would be an interesting undertaking in maths for the folks at surfacestations, but it seems they're more the graphic arts type.

"Climatologists made no attempt to fix the problems with the current network; nor even document them. That's shameful."

Knock off the faux indignation. Whenever anyone asks for money for things like this, hordes of thinktank libertarians ride forth on their free market ponies and yawp about big government and wasting the taxpayers' money.

But make no mistake. The plan is to eliminate current bad stations, then eliminate stations that can't prove a perfect history. The result from the Newsbusters of the world will be this kind of righteous indignation and the rallying cry of the factually defeated: "We just don't know anything. Let's do nothing."

Boris, you gave the best example of your/Dano/Bloom climate warming faith. Current bad stations , Boris, are bad stations. If you want to keep them and criticise anyone who demonstrates they are bad stations, you are nothing more than a faith follower. Boris, suckers abound, mate, look in the mirror.

anon 10:56AM / Paul G said:"Agreed, but the effects should be quantified and the microclimate effects shoud have been documented years ago."What on earth do you think they are doing with the inhomogeneity analysis and corrections? The QUANTITATIVE record of past temperatures and inhomogeneities, are contained in the temperature record. This is why they look for jumps, compare to spatially close stations, and yes, look at the metadata to see if known changes occurred that need to be checked in the actual data, the temperature record, so see if they had an effect.

" The trend is not the issue. The issue is the accuracy of the temperature for the last hundred years. '

The trend is PRECISELY the issue. It makes no never mind, for climate change issues, whether this station measures 4C warmer or cooler than it would if it were out in that open field over there. What matters is precisly the trend over time, and whether a spurious trend has been overlain on the actual trend. Looking at a picture taken today tell us nothing about the history and the changes and when they happened, and theei possible effects on the trend. But looking at the actual data that contains the effects of such changes, and comparing them to spatially related sites and including relevant metadata issue, such as time of day when relevant, CAN do so - and this is what is done. A modern picture taken at a single time point is going to perhaps give us some more info about some possible reasons why there are inhomogeneities IF they have been identified, but they aren't going to identify inhomogeneities themselves - they are useless for that purpose.

The surface stations project seems to start from the unstated assumption that badly sited stations, which certainly may have "incorrect" absolute temps, are ALSO perforce going to have incorrect trends. And then they/you bash the analysts for ignoring QA - when in fact they have been applying huge amounts of QU to finding bad trends, using the best available QUANTITATIVE historical data, which is the actual temperature record.

== anony said: ===="What on earth do you think they are doing with the inhomogeneity analysis and corrections?"==

You mean "homogeneity adjustments" I believe.And you can not correct for what you do not know.

=="This is why they look for jumps . . ."

The global warming signal is in the order of 0.005 to 0.010 degrees annually. It doesn't "jump". And if a surface site temperature "jumps", it is sure as heck time to send someone out there for a much, much closer look. It's not enough to just look at the data, you must look at the individual sites (and not only with satellites).

=="The trend is PRECISELY the issue."==

No, the accurate, representative measurement of temperature at that one site is the issue. Only when that is accomplished can the data be used to properly ascertain trends.

=="But looking at the actual data that contains the effects of such changes, and comparing them to spatially related sites. . ."==

Are the spatially-related sites contamination free? Or is this just a further muddying of the data?

The astounding thing is the apparent lack of enforcement at NOAA/NWS sites. What have climatologists being doing all these years???

You never finished up the tutorial that was going to show why heat capacity was irrelevant (in Tim's blog) in averaging a surface of differening types. Came charging in, but when I asked for the simple "show me on the blackboard", didn't do it.

I know I'm just a dumb solid state chemist, but how about obliging a fellow. Or say you were wrong. Or at least further the discussion.

You don't want to be like a little sophist for the left,. Be for truth, whoever it hurts. Be like Abraham, ready to kill his baby, for the truth.

Since you agree that the Orland data look good, what, in your opinion, is the most plausible explanation for the discrepancies between the Orland and Marysville data? No need for any great detail -- just a quick summary of your "gut feelings" would be fine.

Is John S part of this weather station harassment campaign? If so, his words here should be sent around. He makes it plain what's really going on - and it's most certainly not data gathering or correction.

TCO is a little miffed because Climate Audit has just punched a hole in the faith warmers GISS gods data. However given seeking truth and TCO(and Dano,Bloom,Boris, and yes you Marion) parted company long ago, the old Rabett site is just about right for you all.

TCO, that is rubbish. You and the rest of the faith warmers here have never sought to hold up to scrutiny the GISS data or the high priests that peddle the data. As a recent comment at Climate Audit outlined, the 2000s as the continuous warmest years is now shot. The warmers church is starting to crumble- Boris you still looking for suckers in the mirror!

Hank, you're correct, the recent comments were sound and fury and no substance. The criticism of Watts and SteveM at this site has been atrocious, but actively encouraged. Mine was a silly response. SteveM has produced the audit that the highly paid boffins at GISS should have long ago picked up. That this Rabett site and RC have been so negative of Watts and SteveM is obvious given the GISS connections, maybe now a humbler approach is warranted It is only for the USA mainland, but given GISS produces global anomalous temperature maps, maybe thse maps should be audited a little better now.

And cce, the Arctic is undergoing climate change, as it has done throughout the ages. With the 1930s now having a number of the warmest years , from the American record, maybe the Arctic was under a similiar summer melt regime at that time. There was no A in AGW at that time.

Anonymous, I can not say which is the most plaubible explanation, only the photos of Marysville point to possible multiple microsite contaminants.

A thorough audit would look at station history, instrumentation, microsite influences, etc., at both sites before attempting to explain the discrepancies between the two stations.

That would definitely be worthwhile. But a closer look at the Orland/Marysville data reveals that the greatest discrepancies in the two stations' temperature trends are apparent in the pre-1950's data.

The microsite influences driving the differences between the two stations have waned sharply in the past few decades. In particular, there's a sharp cooling trend for the Orland station (late 1930's to early 1950's) that is not apparent in the Marysville data. Post 1970 or so, the trends for both stations tend to converge.

It is unlikely that the photos at surfacestations.org are going to shed any light on the causes of the discrepancies between the two stations' temperature records.

Because SS photographed the Detroit Lakes, MN surface site a discussion ensued and Steve McIntyre discovered a Y2K error that has resulted in a major adjustment by NASA to the US temperature records from 2000 to 2006. Or didn't you know that?

ecause SS photographed the Detroit Lakes, MN surface site a discussion ensued and Steve McIntyre discovered a Y2K error that has resulted in a major adjustment by NASA to the US temperature records from 2000 to 2006. Or didn't you know that?

You are right -- it is a major adjustment. Instead of 0.9-1.0 C warming over the past 35 years, we are looking at 0.75-0.85 C warming. That's a statistically significant change (the change due to the correction of a stupid programming error that was uncovered as a result of surfacestation.org activities -- credit where credit is due).

Nonetheless, that does not negate the fact that the surfacestation.org folks have made a careless and sloppy comparison between the Orland and Marysville sites.

== cce said: ==="[They're talking about a 0.1-0.2 downward correction of the US temperature numbers since 2000 that McIntyre discovered]"=

And that is a very significant adjustment.- Paul G

cce replied... It is for the 2% of the Earth's surface in question.

But if the records for 2% of the earth's surface are suspect, and caused a 0.1-0.2 downward correction, then how much more of a correction would be needed if measurements for the other 98% are reviewed?

In other words, if corrected measurements from 2% caused a 0.2 degree drop, would corrected measurements from the other 98% cause another 9.8 degree drop?

In other words, if corrected measurements from 2% caused a 0.2 degree drop, would corrected measurements from the other 98% cause another 9.8 degree drop?

The 0.1-0.2 figure applies only to the continental USA. The impact on the global average is miniscule. And remember warming in the continental US has lagged warming on much of the rest of the Earth (i.e. the global avg temp has increased much more than the continental USA's has.) Even so, and even with that 0.15 degree correction, the USA has warmed significantly (on the order of 0.8 deg C) over the past 30-40 years.

Look! Over there! Masses of plants, moving south! Greening up comes later! Arctic ice returns1 Robins no longer in the Arctic, all because the nutters and denialists think their envirohate is validated!

Anonymous asks:"In other words, if corrected measurements from 2% caused a 0.2 degree drop, would corrected measurements from the other 98% cause another 9.8 degree drop?"

Come on guys. If this is tripping you up, you haven't paid attention to anything that has been said.

It was a .1 to .2 degree drop in the calculated temperature anomaly of 2% of the Earth's surface (the US). Global temperatures won't be affected by any appreciable amount. 2005 will remain the hottest year in GISS' global temperature records.

If global temperatures were actually 9.8 degrees lower than we thought, we'd be in another ice-age, but just didn't know it.

All the faith warmers thrashing about- great to see. Dano forgets to take his tablets and starts to see birds, insects, grass moving all all directions and at all times of the year. TCO gets all equivocal and Boris gets all a quiver. And this is all for free.

The US represents 2% of the land surface and it is the most highly sampled area with argueably the best most open historical records.

So a group of rank amateurs take photos of a small sampling of sites in this high quality US network. The photos cause them to question the data. A retired mining executive looks at the data and finds an unrelated mistake in the US land recrd. A mistake made by climate scientists. NASA no lessGuys who shouldnt make mistakes. They are not 15 year old girls hand drawing charts. They are experts, priests. So, the mistake results in the reordering of the US record.

So, 200 or so sites of the 1221 sites are examined in the US Which is 2% of the land mass of the world. And the mistake found in that little rabbitt patch, turns out to make the 1930s hotter than today. Math being math, the global impact is small. Reason being reason, we can well expect that a full audit of the US will turn up more and a full audit of the world, especially china, will turn up even more.

Math being math, the global impact is small. Reason being reason, we can well expect that a full audit of the US will turn up more and a full audit of the world, especially china, will turn up even more.

Measurement errors being normally distributed, it won't make a difference in the aggregate.

Unless it should turn out the entire basis for the "greenhouse effect" in replicated laboratory experiments is flawed. And while you're working on that, see if you can build a perpetual motion machine.

"because the nutters and denialists think their envirohate is validated!"

that must be the easiest way for you to look at it. i live about 30 miles from love canal, and about 5 miles from another Superfund landfill. i have worked in remediation of chemical dumpsites. have you?

look, i keep things clean. i dont litter, i plant trees and plants on my land (a good-sized piece). i support groups who actually DO things besides name-call. i enjoy clean air and water. and i try to educate others i see outdoors who are less informed.

to call me a nutter, denier, or full of envirohate is pretty galling. first, you are so objectively uninformed, and your statements are dead false. i have looked at the science, and the maths within my ability (admittedly, well below mcintyre level). CO2-caused AGW does not add up. it provides a small component to the present warming. RP jr has calculated the max at around 28%, i believe. that is really too high, in my opinion. CO2 contribution, when most of the science and math are done, will max out at 8% or so.

"Measurement errors being normally distributed, it won't make a difference in the aggregate."

this was not a measurement error. this was (mostly) a programming error. the measurement errors have been corrected by an unknown function(s). when this (these) is/are audited, other correction will almost certainly be forthcoming.

"What I looked at was how the long grass was moving. There clearly was a difference directly in front of the unit, but more than 20 degrees to the side there was none. That is a scientific observation. You can clearly see the same thing in the Schlieren."

did you use a square to measure "straight out"? what kind?did you use a protractor to measure 20 degrees? what kind? did the effect cease at 1 degree off square, 5 degrees, 19 degrees, or what? THAT would have been a scientific observation. what you did is called "arm-waving".

Hey, guys, I lost the password to the secret site where all of us warmers like Boris, Lee, Tim, BCL, Eli, Gavin, etc. exchange notes and strategy. Could someone post it please. I need to get back on the circuit. I'll let you know when I've seen it and then you can take it down. Thanks.

Good man TCO. Your recent wishy-washiness was poor form. The faith warmers need you again. Old fruitloop Dano has been bravely thrashing away, but you know what he's like when he forgets those tablets.

But you're missing the obvious. The men from GISS gave you the blink several years ago when the dodgy Y2K corrections were made to make the warmest years in a million- billion years. Some buggar of an amateur sluth finds out, and now Gavin is blinking like no mans business again. Bloomy's toiling manfully out there, you know, 2% of surface mass, globals unchanged etc, etc.

Come on TCO, shoulder to the grindstone, nose to the plough, message to be got out there is warmest in a billion-zillion years.

TheoMeasurement errors being normally distributed, it won't make a difference in the aggregate.

That's true when you're measuring blocks of wood or counting photons, but I'm not sure how this relates to sites that gradually become more urban over time and have parking lots next to them. Those are foreign intrusions -- are they properly accounted for?

Interesting comment boris. Highly paid boffins at GISS have this data for several years, are always doing reviews and updates of temperature information( as said by GavinS at RC) and missed(?) the obvious. The conspiracy is not on the skeptics side old son. We don't take the raw temp data , manipulate it and then send it out for public release.Naive manipulation said GISS in response to SteveM. Why are highly paid boffins paid to do naive work?

Of course, why should the gang at NASA have noticed the error? I expect scientists most often find mistakes in the data when there is an anomaly to be explained, e.g., the data is in disagreement with either theory or other measurements. This adjustment doesn't seem to change basic conclusions in any significant manner. Rather, the data set has simply been made more robust.

The NASA gang assuredly has lots of data coming in all the time that they have to analyze. It's not like they are going to focus a lot of energy on one data set just to find errors that don't affect basic conclusions.

Actually, under the assumption that the most significant errors will be the easiest to find, I'm impressed that the data is so robust that this is the worst that could be found.

i wont burden everyone with math here. rp jrs site has it spelled out at a max of 28%, which he thinks is too high relative to reality.

suffice it to say (in this format) that all models must assume feedbacks in order to come up with the projected effect of +100 pmm CO2. (much less than the commonly stated effect of 2XCO2). these feedbacks are always assumed (with poorly defined terms) as being positive feedbacks. the largest known feedback (H2O/clouds) have an unknown effect. even the SIGN of this feedback is unknown.

but like i said, have a look at pielke. it's a good part of the debate. thanks for the question.

The NASA gang assuredly has lots of data coming in all the time that they have to analyze. It's not like they are going to focus a lot of energy on one data set just to find errors that don't affect basic conclusions."

Do I take this to mean that as long as the data supports their conclusion of global warming, that they don't need to see if the data is wrong?

Anonymous 11:17 AM said:"Do I take this to mean that as long as the data supports their conclusion of global warming, that they don't need to see if the data is wrong?"

You might, but it is not what I was saying. :)

There can be little doubt that the data sets are very carefully analyzed. After that careful analysis is completed, it makes very little sense to go looking for insignificant errors at a later time, unless there is some reason to suspect identifiable errors are there. (In this case, McIntyre provided such a reason.)

This applies to both errors that would increase or decrease the calculated warming trends. There might still be errors in the data set which would lead to a slightly larger (or smaller) value for US warming, but they aren't worth looking for unless there is a reason to suspect they're there and a way to identify them is available.

Note that the above is my intuition concerning insignificant errors, i.e., errors that won't change the conclusions. Significant errors are another story, and scientists should always be on the lookout for errors large enough to change their conclusions. At this point, however, it seems extremely unlikely that these data sets could contain such an error.

The people who are still questioning the reality of global warming are just delusional -- idiotic, really. Such "skepticism" is not science. It's is ideology, idiocy or a combination thereof.

The surface record is just one line of evidence among many that indicate a warming trend over the past century and particulalry over the past 30 years when the greenhouse forcing was ramping up significantly.

To say nothing of the fact that minor errors in the surface temperature record for the continental US (which comprises something like 2% of the earth's total surface) don't mean squat as far as the basic conclusion about warming goes.

Anonymous 2:57 PM:"The trend is PRECISELY the issue. It makes no never mind, for climate change issues, whether this station measures 4C warmer or cooler than it would if it were out in that open field over there. What matters is precisly the trend over time, and whether a spurious trend has been overlain on the actual trend. Looking at a picture taken today tell us nothing about the history and the changes and when they happened, and theei possible effects on the trend. But looking at the actual data that contains the effects of such changes, and comparing them to spatially related sites and including relevant metadata issue, such as time of day when relevant, CAN do so - and this is what is done. A modern picture taken at a single time point is going to perhaps give us some more info about some possible reasons why there are inhomogeneities IF they have been identified, but they aren't going to identify inhomogeneities themselves - they are useless for that purpose."

If a given site has nearby air conditioners, we may or may not be able to research its HVAC history, but we know it almost certainly didn't have them 50 years ago, don't we?

If a given site has asphalt, we know it almost certainly didn't have it 80 years ago, don't we?

So if a site has been around for 100 years, and we're using it to prove that, say, temperatures have increased by 0.6 C in the past 100 years, it would be worth knowing that during that time AC and asphalt has been added, would it not?

Indeed, wouldn't this info tell us much more about the accuracy of the past century's temperature record than could any attempt to track future trends (which will be nonexistent if the site merely maintains its current level of AC and asphalt) with a new network of properly built stations?

Back on the original post, that "trash burn barrel" five feet from a weather station.

http://www.norcalblogs.com/watts/images/Tahoe_city3.JPG

It's on a wooden pallet. There are no scorch marks on the wood. I know burning anything in a steel drum like that would leave scorch marks on the wooden slats. It _could_not_ have been used as pictured. It must have been brought there with a forklift on the pallet.

But Hank, wouldn't that be like getting a response of one felow at one time? Was the pallet on which the drum now stands always the pallet on which it stood? Was the drum always at that site, but only put on that pallet recently? Was the maintainence man away when fires were lit, and so he may not know if the drum was fired up?

What, you actually mean that the temperature recording stations should be examined in the field, and faith warmers should check what is happening at the sites? But Hank that is heresy, and you are are more than supportive of the faith warmers at this and the RC site.

Get of your backside, Hank and go and do some of the work you ask others to do. See how bad the recording sites really are. Drums on pallets will pale into insignificence, old son.

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Eli Rabett

Eli Rabett is a not quite failed professorial techno-bunny, a chair election from retirement, at a wanna be research university that has a lot to be proud of but has swallowed the Kool-Aid. The students are naive but great and the administrators vary day-to-day between homicidal and delusional. His colleagues are smart, but they have a curious inability to see the holes that they dig for themselves. Prof. Rabett is thankful that they occasionally heed his pointing out the implications of the various enthusiasms that rattle around the department and school. Ms. Rabett is thankful that Prof. Rabett occasionally heeds her pointing out that he is nuts.